Formation of insulator oxide films with acid or base catalyzed hydrolysis of alkoxides in supercritical carbon dioxide

ABSTRACT

Metal and/or silicon oxides are produced by hydrolysis of alkoxide precursors in the presence of either an acid catalyst or a base catalyst in a supercritical fluid solution. The solubility of the acid catalysts in the supercritical fluid can be increased by complexing the catalyst with a Lewis base that is soluble in the supercritical fluid. The solubility of the base catalysts in the supercritical fluid can be increased by complexing the catalyst with a Lewis acid that is soluble in the supercritical fluid. The solubility of water in the solution is increased by the interaction with the acid or base catalyst.

BACKGROUND OF THE INVENTION

Insulator oxide films, particularly silicon oxide films, haveconventionally been made by methods such as thermal oxidation ofsilicon, physical vapor deposition and chemical vapor deposition, mosttypically chemical vapor deposition. However, chemical vapor depositionrequires high temperatures, e.g., above 300° C., even with the aid of aplasma. Newer, lower temperature techniques, known as Chemical FluidDeposition (CFD), are based on chemical deposition of the oxide filmsfrom a supercritical fluid solution have been developed.

U.S. Pat. No. 4,970,093 describes a method for depositing a film of adesired material on a substrate comprises dissolving at least onereagent in a supercritical fluid comprising at least one solvent. Eitherthe reagent is capable of reacting with or is a precursor of a compoundcapable of reacting with the solvent to form the desired product, or atleast one additional reagent is included in the supercritical solutionand is capable of reacting with or is a precursor of a compound capableof reacting with the first reagent or with a compound derived from thefirst reagent to form the desired material. The supercritical solutionis expanded to produce a vapor or aerosol and a chemical reaction isinduced in the vapor or aerosol so that a film of the desired materialresulting from the chemical reaction is deposited on the substratesurface. In an alternate embodiment, the supercritical solutioncontaining at least one reagent is expanded to produce a vapor oraerosol which is then mixed with a gas containing at least oneadditional reagent. A chemical reaction is induced in the resultingmixture so that a film of the desired material is deposited.

U.S. Pat. No. 5,789,027 describes methods for depositing a film ofmaterial on the surface of a substrate by i) dissolving a precursor ofthe material into a supercritical or near-supercritical solvent to forma supercritical or near-supercritical solution; ii) exposing thesubstrate to the solution, under conditions at which the precursor isstable in the solution; and iii) mixing a reaction reagent into thesolution under conditions that initiate a chemical reaction involvingthe precursor, thereby depositing the material onto the solid substrate,while maintaining supercritical or near-supercritical conditions. Theinvention also includes similar methods for depositing materialparticles into porous solids, and films of materials on substrates orporous solids having material particles deposited in them.

U.S. Pat. No. 6,541,278 describes a semiconductor substrate is placedwithin a housing. By supplying organometallic complexes and carbondioxide in a supercritical state into the housing, a BST thin film isformed on a platinum thin film, while at the same time, carboncompounds, which are produced when the BST thin film is formed areremoved. The solubility of carbon compounds in the supercritical carbondioxide is very high, and yet the viscosity of the supercritical carbondioxide is low. Accordingly, the carbon compounds are removableefficiently from the BST thin film. An oxide or nitride film may also beformed by performing oxidation or nitriding at a low temperature usingwater in a supercritical or subcritical state, for example.

U.S. Pat. No. 6,716,663 describes a method wherein a semiconductorsubstrate is placed within a housing. By supplying organometalliccomplexes and carbon dioxide in a supercritical state into the housing,a BST thin film is formed on a platinum thin film, while at the sametime, carbon compounds, which are produced when the BST thin film isformed, are removed. The solubility of carbon compounds in thesupercritical carbon dioxide is very high, and yet the viscosity of thesupercritical carbon dioxide is low. Accordingly, the carbon compoundsare removable efficiently from the BST thin film. An oxide or nitridefilm may also be formed by performing oxidation or nitriding at a lowtemperature using water in a supercritical or subcritical state, forexample.

Although these methods of chemical deposition form supercritical fluidsolutions provide advantages over conventional deposition techniques,they can still be improved. In particular, faster reaction/depositionrates are desired. Also, providing a broader array of precursors andreagents would also be advantageous.

BRIEF SUMMARY OF THE INVENTION

A hallmark of the present invention is the rapid deposition of oxideformations via acid or base catalyzed CFD processes.

In one embodiment, the invention is a method for forming an insulatingstructure, the method comprising hydrolyzing an alkoxide in asupercritical fluid in the presence of an acid catalyst or a basecatalyst such that an insulating oxide material is deposited from thesupercritical fluid to form the insulating structure.

Another embodiment of the invention is a composition comprising asolution of an alkoxide and either an acid or a base in supercriticalcarbon dioxide.

A further embodiment of the invention is a method of forming a materialhaving a high dielectric content, the method comprising the steps offorming a solution of a hydrolysable alkoxide and a catalyst, thecatalyst comprising an acid or a base, in supercritical carbon dioxide;and, reacting the hydrolysable alkoxide with water to deposit an oxidehaving a dielectric constant at least about 10.

Another embodiment of the invention is a method of producing aninsulating film, the method comprising forming a solution of ahydrolysable alkoxide and a catalyst, the catalyst comprising an acid ora base, in supercritical carbon dioxide; contacting a substrate with thesupercritical carbon dioxide solution; and, reacting the hydrolysablealkoxide with water to deposit a film of an oxide having a dielectricconstant at least equal to silicon dioxide.

Yet another embodiment is a method for producing fine structures of aninsulating material, the method comprising forming a solution of ahydrolysable alkoxide and a catalyst, the catalyst comprising an acid ora base, in supercritical carbon dioxide; contacting a substrate with thesupercritical carbon dioxide solution, wherein the substrate comprisesstructures having high aspect ratios of at least 5; and, reacting thehydrolysable alkoxide with water to deposit an oxide having a dielectricconstant at least equal to silicon dioxide, wherein the oxide fills thehigh aspect ratio structures.

In a further embodiment, the invention is a method of increasing thesolubility of acids in supercritical carbon dioxide, the methodcomprising combining supercritical carbon dioxide, a Lewis base that issoluble in supercritical carbon dioxide, and an acid that issubstantially insoluble in supercritical carbon dioxide such that theLewis base and the acid form a complex that is soluble in supercriticalcarbon dioxide.

Another embodiment is a method of increasing the solubility of bases insupercritical carbon dioxide, the method comprising combiningsupercritical carbon dioxide, a Lewis acid that is soluble insupercritical carbon dioxide, and a base that is substantially insolublein supercritical carbon dioxide such that the Lewis acid and the baseform a complex that is soluble in supercritical carbon dioxide.

Yet another embodiment is a method for increasing the solubility ofwater in supercritical carbon dioxide, the method comprising combiningsupercritical carbon dioxide with an acid or base, wherein the acid orbase is soluble, or solubilizable, in supercritical carbon dioxide andthe acid or base interacts with water to solubilize the water in thesupercritical carbon dioxide.

Still yet another embodiment is a method of forming a material having alow dielectric content, the method comprising the steps of forming asolution of a hydrolysable alkoxide and a catalyst, the catalystcomprising an acid or a base, in supercritical carbon dioxide, andreacting the hydrolysable alkoxide with water to deposit an oxide havinga dielectric constant less than about 3.

Various other features, objects and advantages of the present inventionwill be made apparent from the following detailed description and thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, references made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and thatstructural, logical and electrical changes may be made without departingfrom the spirit and scope of the present invention.

FIGS. 1A-D show SEM images of a silicon dioxide film formed by a methodof this invention.

DETAILED DESCRIPTION OF THE INVENTION

This invention is an improved method of conducting chemical reactions insupercritical, or near supercritical, carbon dioxide (SCD). In onepreferred embodiment, the invention is a method for producing metal orsemi-metal oxide deposits by hydrolysis of at least one hydrolysableprecursor in supercritical carbon dioxide (SCD). Specifically, thehydrolysis reaction can be catalyzed by the presence of either an acidor a base.

The hydrolysable precursor is a typically a hydrolysable metalliccompound. As used herein, the terms “metal” and “metallic” are to beconstrued broadly to encompass metals, the semi-metals (also known asmetalloids) and phosphorus. The semi-metals are typically considered tobe boron, silicon, germanium, arsenic, antimony, tellurium, andpolonium.

The hydrolysable metallic compound precursor must be soluble orpartially soluble in supercritical carbon dioxide (SCD). Unlike a normalfluid solvent, SCD has virtually no surface tension. As such, SCD isfreely miscible with all gases because of the mutual lack of surfacetension. Therefore, the terms “solubility” and “soluble” are used in thebroadest sense to mean the ability or tendency of one substance to blenduniformly with another and the term “solution” is used to designate bothtrue solutions (i.e., solids dissolved in a solvent) and uniformmixtures of miscible fluids. The SCD may include one or more co-solventssuch as an alcohol (e.g., methanol, ethanol, etc.) or other semi-polarsolvent (e.g., acetone) added to further aid in dissolution of the metalalkoxide, metal complex or salt. Additionally, this method could beapplicable to reverse micelle structures that contain a CO₂ immisciblesolvent that is the carrier for one or more of the reactants. Sometypical surfactants for a reverse micelle in SCD arebis-(2-ethylhexyl)sulfosuccinate (AOT), Zonyl FSJ (contains one or morefluoroalkylphosphate ester salt), and poly(1,1-dihydroperfluoro octylacrylate)-b-poly(ethylene oxide) and others in review article: Helen M.Woods, Marta M. C. G. Silva, Cécile Nouvel, Kenin M. Shakesheff andStven M. Howdle, Materials processing in supercritical carbon dioxide:surfactants, polymers and biomaterials, J. Mater. Chem., 2004, 14 (11),1663-1678.

Generally, the hydrolysable metallic compounds known from the field ofSol-Gel chemistry should be appropriate for use in this inventive methodunder the right processing conditions. Examples of such compounds are:

1) Metal alkoxide with the structure M(OR)_(n) such as ethoxides (OEt),propoxides (OPr), butoxides (OBu), etc, and associated oligomers species[M(OR)_(n)]_(m), where M is at least one metal atom, R is any alkylgroup and may be the same or different each occurrence, and m and n areconstants that are determined as needed to balance the electroniccharge. Preferably, M is at least one of silicon, boron, hafnium,aluminum, phosphorus, zirconium, titanium, barium, lanthanum, oryttrium. Typically, R is a methyl, ethyl, propyl, or butyl group. Anon-limiting list of suitable metallic alkoxides includes silicon tetraalkoxy compounds (such as tetraethyl orthosilicate (TEOS),tetramethoxysilane (TMOS), tetrapropoxysilane (TPOS), andtetrabutyloxysilane (TBOS)), hafnium tert-butoxide, aluminum ethoxideand aluminum isopropoxide. These and other metallic alkoxides arecommercially available, such as from Gelest, Inc. More than one metallicalkoxide precursor may be used when a complex oxide, e.g., BST, is to bedeposited. M-O-M linkages can exist in these materials, as well.Included are reaction products of metal alkoxides with organic hydroxycompounds such as alcohols, silanols R₃SiOH, glycols OH(CH₂)_(n)OH,carboxylic and hydroxycarboxylic acids, hydroxyl surfactants etc.

2) Metal carboxylates M(O₂COR)_(n), and carboxylate oligomers andpolymers [M(O₂CR)_(n)]_(m), as well as hydrates thereof, where M is atleast one metal atom, R is any alkyl group and may be the same ordifferent each occurrence, and m (m stands for the degree of associationor molecular complexity or nuclearity) and n are constants that aredetermined as needed to balance the electronic charge.

3) Metal β-diketonates [M(RCOCHCOR′)_(n)] and oligomeric and polymericmaterials [M(RCOCHCOR′)_(n)], as well as adductsM(β-diketonates)_(n)L_(x) where M is at least one metal atom, R and Ŕare any alkyl group and may be the same or different each occurrence, nis a constant determined as needed to balance the electronic charge, andL usually has a nitrogen or oxygen donor sites such as water, alcohols,ethers, amines, etc.

4) Metal alkoxide derived heteroleptic species (i.e., species withdifferent types of ligands) such as M(OR)_(n-x)Z_(x) (Z=β-diketonates orO₂CR), where M is at least one metal atom, R is any alkyl group and maybe the same or different each occurrence, and m and x are constants thatare determined as needed to balance the electronic charge.

5) ORganically MOdified SILanes (ORMOSILS) of general formula(RO)_(4-x)SiZ_(x) where R is any alkyl group, Z is another functional(e.g. acrylate, epoxide, vinyl, etc) or non-functional alkyl groupforming a stable Si—C bond, and x is a constant chosen to balanceelectronic charge.

6) Heterometallic precursors (M_(x)M_(y)′, M_(x)M_(y)′M_(z)″) with suchforms as, but not limited to M_(x)M′_(y)(OR)_(n), where M, M′ and M″ aredifferent metal atoms, R is any alkyl group and may be the same ordifferent each occurrence, and n, x, y, and z are constants that aredetermined as needed to balance the electronic charge.

7) metal salts, halides MX_(n), chlorates, hypochlorites, nitrates,nitrites, phosphates, phosphites, sulfates, sulfites, etc., where M is ametal atom, X is a halide atom and n is a constant determined as neededto balance the electronic charge.

Non-hydrolytic condensation reactions are also possible with theseSol-Gel materials. Building-up of the M-O-M network can also be achievedby condensation reactions between species with different ligands. Metalalkoxides and carboxylates (elimination of ester, equation 1), metalhalides MX_(n) and alkoxides (formation of alkylhalide—equation 2) orelimination of dialkylether (equation 3) as the source of the oxo ligandare examples.M(OR)_(n)+M′(O₂CR′)_(n)--->(OR)_(n−1)M-O-M′(O₂CR′)_(n−1)+RCO₂R  (1)M(OR)_(n)+M′X_(b)--->(OR)_(n−1)M-O-M′X_(n−1)+RX  (2)M[OSi(OR)₃]n--->MO_(n/2)+SiO₂+R₂O under applied heat  (3)Metal alkoxides can also be used as precursors of non-oxide materials.For instance, fluorinated alkoxides M(OR_(f))_(n) (R_(f)=CH(CF₃)₂, C₆F₅,. . . ) can decompose upon heating to give the base metal. Metalfluorides may result from these precursors depending on thermaltreatment. The reactivity of the M-OR bond also provides ascention tophosphatessulfides or oxysulfides materials.

The hydrolysable metallic alkoxide precursors are selected so that theyyield the desired metallic oxide material. The metallic oxide materialsmay have high k values (dielectric constant), baseline values, or low kvalues. The high k value materials deposited by the hydrolysis reactionshave k values at least equal to about 10. Typical of such high k valuematerials are typically oxides, such as, for example, Ba—Sr—Ti—O (BST),Pb—Zr—Ti—O (PZT), and certain low atomic number metal oxides or mixedmetal oxides, such as titanium oxide, hafnium oxide, zirconium oxide,aluminum oxide or hafnium-aluminum oxide. Silicon dioxide is generallyconsidered the baseline material having a k value of around 4. Otherbaseline materials include boron phosphosilicate glass (BPSG) andphosphosilicate glass (PSG). Low k value materials (k less than about 3)can be derived from these materials by incorporating fluorine and/orcarbon and/or porosity. Other low k value materials possible by thisinvention are hybrid inorganic-organic glasses that incorporatemetal-organic bonds into the material. Representative of such hybridglasses are organically modified silicate (Ormosil), organicallymodified ceramic (Ormocer), and silicon silsesquioxane materials.

The catalysts are acids or bases that are either soluble insupercritical carbon dioxide or are soluble when part of a Lewisacid-Lewis base complex. Suitable acids include organic acids, such asacetic acid, formic acid, and citric acid, as well as inorganic acidssuch as hydrofluoric acid (gaseous at the critical temperature of SCD),hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. Manyorganic acids, and hydrofluoric acid, are soluble in supercriticalcarbon dioxide. Likewise, chlorine and bromine are gaseous at thecritical temperature of SCD and form acids in contact with water). Incontrast, many inorganic acids, especially strong inorganic acids, arenot normally soluble in supercritical carbon dioxide. Such SCD-insolubleacids can form SCD-soluble complexes with SCD-soluble Lewis Bases. Aparticularly useful Lewis Base for forming these SCD-soluble complexesis tributyl phosphate. Tributyl phosphate is highly soluble in SCD andthe inventors believe that the phosphate group can attach to acids, suchas nitric acid or HCl, to increase the solubility of the acid by ordersof magnitude. Suitable bases include ammonia, organic amines, pyridineor substituted pyridine, and fluoroamines. Strong inorganic bases, suchas hydroxides, e.g., KOH or NaOH, can be used if they are solubilized bycomplexing with a Lewis acid that is soluble in supercritical carbondioxide.

Generally, the hydrolysis reactions are limited by the low solubility ofwater in supercritical carbon dioxide. The scarcity of available waterdue to the low SCD-solubility of water is believed to be a major causeof the relatively slow reaction rates seen in earlier processes that didnot use the current catalysts. For example, metal alkoxides arewell-known to be moisture sensitive. Indeed, metal alkoxides willtypically undergo hydrolysis slowly at room temperature and would beexpected to rapidly hydrolyze at 100° C., even in the absence of acatalyst, if water was readily available.

In contrast to the previous art, in this method, the SCD-soluble acids,bases and/or acid/base-complexed catalysts interact with watermolecules, so that the SCD-soluble catalysts work as carriers for waterdelivery in supercritical CO₂. This interaction greatly increases theavailability of water for the hydrolysis reaction, which results in thedesired increase in the hydrolysis reaction rate. For example, ammoniaappears to have at least a one-to-one molecular interaction with waterso that, on average, each dissolved ammonia molecule carries at leastone water molecule.

The new acid or base catalyzed oxide deposition process in supercriticalfluid is carried out in a high-pressure system with CO₂ pressure atleast at the critical pressure of about 73 atm, typically greater than80 atm. The concentrations of the precursors (alkoxides) and waterdissolved in the supercritical fluid phase are usually high (severalhundred torrs or more) and consequently result in high deposition ratesin relatively low temperatures. Preferably the reaction temperature isno more than about 150° C., more preferably no more than about 100° C.

When using the process of this invention, the deposition rate isgenerally fast, in the order of several hundred angstroms per minute.The oxide films formed by this method show good morphology and strongadhesion to silicon or other substrate surfaces. This method also allowsdeposition of oxides in fine structures of silicon wafers with highaspect ratios. The high diffusivity and low viscosity of supercriticalcarbon dioxide enables oxide deposition in small areas and finestructures with high aspect ratios. FIG. 1 shows SEM images of silicondioxide films formed on a silicon wafer and also deposited in the smallstructures (100 nm wide and 500 nm deep trenches). As shown in FIG. 1,the silicon dioxide films are basically free of visible voids accordingto the SEM micrographs.

Although the oxide films produced by this method are typically free oflarge voids, the films are porous as indicated by the density of thedeposited material. However, due to the lack of surface tension in SCD,the drying occurs without contractional forces from the liquid. As aresult, the deposit material does not display “mud-cracking” typical ofthe drying of a normal fluid solvent. Generally, the oxide films formedby base catalyzed reactions are denser than the oxide films formed byacid catalyzed reactions. The densities of the oxide layers formed in bythis inventive process are believed to be greater than 50% of thedensity of dense SiO₂ (2.2 g/cm³).

Representative examples of acid or base catalyzed oxide formationreactions are described as follows:

SiO₂ Film FormationSi(OCH₂CH₃)₄+2H₂O ^(acid) SiO₂+4CH₃CH₂OH

When acetic acid is used as the catalyst, a smooth silicon dioxide filmwith reasonable thickness can be formed in supercritical CO₂ attemperatures above 100° C. The deposition reaction actually starts atroom temperature but produces good quality thick films at 100° C. In theabsence of acetic acid, only uneven and thin silicon dioxide films(10-20 nm) can be formed. Addition of acetic acid makes the resultingsilicon dioxide films uniform and thick. The thickness of the silicondioxide films formed by reaction (1) can be up to 500 nm in the presenceof 19 mole % to 95 mole % of acetic acid relative to TEOS. The acidcatalytic reaction probably involves proton coordination to the oxygenatoms of TEOS molecule that facilitates the hydrolysis.

SiO₂ Film Formation

Alkoxide: tetraethyl orthosilicate (TEOS); Base catalyst: NH₃Si(OCH₂CH₃)₄+2H₂O

SiO₂+4CH₃CH₂OH

HfO₂ Deposition

Alkoxide: Hafnium tert-butoxide; Base catalyst: NH₃Hf[OC(CH₃)₃]₄+2H₂O

HfO₂+4(CH₃)₃COH

Al₂O₃ Deposition

Alkoxide: (a) Aluminum ethoxide and (b) Aluminum isopropoxide; Basecatalyst: NH₃

(a) Aluminum Ethoxide2(C₂H₅O)₃Al+3H₂O

Al₂O₃+6CH₃CH₂OH

(b) Aluminum Isopropoxide2[(CH₃)₂CHO]₃Al+3H₂O

Al₂O₃+6(CH₃)₂CHOH

In compliance with the statute, the invention has been described inlanguage more or less specific as to chemical, structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred embodiments of putting the inventioninto effect. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that changesmay be made without departing from the spirit and scope of the presentinvention. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method for forming an insulating structure, the method comprising:hydrolyzing an alkoxide in a supercritical fluid in the presence of anacid catalyst or a base catalyst such that an insulating oxide materialis deposited from the supercritical fluid to form the insulatingstructure.
 2. The method of claim 1, wherein the supercritical fluid issupercritical carbon dioxide.
 3. The method of claim 1, wherein thealkoxide comprises at least one of the groups of elements consisting ofsilicon, titanium phosphorus, hafnium, zirconium, aluminum and boron. 4.The method of claim 1, wherein the alkoxide is tetraethyl orthosilicate.5. The method of claim 1, wherein the alkoxide is hafnium tert-butoxide.6. The method of claim 1, wherein the alkoxide is aluminum ethoxide. 7.The method of claim 1, wherein the alkoxide is aluminum isopropoxide. 8.The method of claim 1, wherein the acid catalyst is soluble insupercritical carbon dioxide or can be rendered soluble when complexedwith a Lewis base.
 9. The method of claim 8, wherein the acid catalystis complexed with a Lewis base and the Lewis base is tributyl phosphate.10. The method of claim 1, wherein the acid catalyst is acetic acid,formic acid, citric acid, hydrofluoric acid, hydrochloric acid, nitricacid, sulfuric acid, or phosphoric acid.
 11. The method of claim 1,wherein the acid catalyst is acetic acid.
 12. The method of claim 1,wherein the base catalyst is soluble in supercritical carbon dioxide orcan be rendered soluble by complexing with a Lewis acid.
 13. The methodof claim 1, wherein the base catalyst is at least one of ammonia,organic amines, pyridine or substituted pyridine, fluoroamines, orhydroxides.
 14. The method of claim 1 wherein the base catalyst isammonia.
 15. The method of claim 1, wherein the reaction temperature isat least 100° C.
 16. A composition comprising a solution of an alkoxideand either an acid or a base in supercritical carbon dioxide.
 17. Thecomposition of claim 16, wherein the solution further comprises water.18. The composition of claim 16, wherein the acid is essentiallyinsoluble in supercritical carbon dioxide but is soluble insupercritical carbon dioxide when complexed with a Lewis base.
 19. Amethod of forming a material having a high dielectric content, themethod comprising the steps of: forming a solution of a hydrolysablealkoxide and a catalyst, the catalyst comprising an acid or a base, insupercritical carbon dioxide; and, reacting the hydrolysable alkoxidewith water to deposit an oxide having a dielectric constant at leastabout
 10. 20. The method of claim 19, wherein the alkoxide comprises atleast one of the groups of elements consisting of silicon, titaniumphosphorus, hafnium, zirconium, aluminum and boron.
 21. The method ofclaim 19, wherein the alkoxide is tetraethyl orthosilicate.
 22. Themethod of claim 19, wherein the alkoxide is hafnium tert-butoxide. 23.The method of claim 19, wherein the alkoxide is aluminum ethoxide. 24.The method of claim 19, wherein the alkoxide is aluminum isopropoxide.25. The method of claim 19, wherein the acid catalyst is soluble insupercritical carbon dioxide or can be rendered soluble when complexedwith a Lewis base.
 26. The method of claim 25, wherein the acid catalystis complexed with a Lewis base and the Lewis base is tributyl phosphate.27. The method of claim 25, wherein the acid catalyst is acetic acid,formic acid, citric acid, hydrofluoric acid, hydrochloric acid, nitricacid, sulfuric acid, or phosphoric acid.
 28. The method of claim 19,wherein the acid catalyst is acetic acid.
 29. The method of claim 19,wherein the base catalyst is soluble in supercritical carbon dioxide orcan be rendered soluble by complexing with a Lewis acid.
 30. The methodof claim 19, wherein the base catalyst is at least one of ammonia,organic amines, pyridine or substituted pyridine, fluoroamines, orhydroxides.
 31. The method of claim 19, wherein the base catalyst isammonia.
 32. The method of claim 19, wherein the reaction temperature isat least 100° C.
 33. An intermediate for depositing a high dielectricconstant material, the intermediate comprising a hydrolysable alkoxideand a catalyst comprising an acid or a base in a supercritical carbondioxide solution, wherein the hydrolysable alkoxide reacts with water toyield an oxide having a dielectric constant at least about
 10. 34. Themethod of claim 33, wherein the alkoxide comprises at least one of thegroups of elements consisting of silicon, titanium phosphorus, hafnium,zirconium, aluminum and boron.
 35. The method of claim 33, wherein thealkoxide is tetraethyl orthosilicate.
 36. The method of claim 33,wherein the alkoxide is hafnium tert-butoxide.
 37. The method of claim33, wherein the alkoxide is aluminum ethoxide.
 38. The method of claim33, wherein the alkoxide is aluminum isopropoxide.
 39. The method ofclaim 33, wherein the acid catalyst is soluble in supercritical carbondioxide or can be rendered soluble when complexed with a Lewis base. 40.The method of claim 39, wherein the acid catalyst is complexed with aLewis base and the Lewis base is tributyl phosphate.
 41. The method ofclaim 33, wherein the acid catalyst is acetic acid, formic acid, citricacid, hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid,or phosphoric acid.
 42. The method of claim 33, wherein the acidcatalyst is acetic acid.
 43. The method of claim 33, wherein thereaction temperature is at least 100° C.
 44. The method of claim 33,wherein the base catalyst is soluble in supercritical carbon dioxide orcan be rendered soluble by complexing with a Lewis acid.
 45. The methodof claim 33, wherein the base catalyst is at least one of ammonia,organic amines, pyridine or substituted pyridine, fluoroamines, orhydroxides.
 46. The method of claim 33, wherein the base catalyst isammonia.
 47. A method of producing an insulating film, the methodcomprising forming a solution of a hydrolysable alkoxide and a catalyst,the catalyst comprising an acid or a base, in supercritical carbondioxide; contacting a substrate with the supercritical carbon dioxidesolution; and, reacting the hydrolysable alkoxide with water to deposita film of an oxide.
 48. The method of claim 47, wherein the alkoxidecomprises at least one of the groups of elements consisting of silicon,titanium phosphorus, hafnium, zirconium, aluminum and boron.
 49. Themethod of claim 47, wherein the alkoxide is tetraethyl orthosilicate.50. The method of claim 47, wherein the alkoxide is hafniumtert-butoxide.
 51. The method of claim 47, wherein the alkoxide isaluminum ethoxide.
 52. The method of claim 47, wherein the alkoxide isaluminum isopropoxide.
 53. The method of claim 47, wherein the acidcatalyst is soluble in supercritical carbon dioxide or can be renderedsoluble when complexed with a Lewis base.
 54. The method of claim 53,wherein the acid catalyst is complexed with a Lewis base and the Lewisbase is tributyl phosphate.
 55. The method of claim 47, wherein the acidcatalyst is acetic acid, formic acid, citric acid, hydrofluoric acid,hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid. 56.The method of claim 47, wherein the acid catalyst is acetic acid. 57.The method of claim 47, wherein the base catalyst is soluble insupercritical carbon dioxide or can be rendered soluble by complexingwith a Lewis acid.
 58. The method of claim 47, wherein the base catalystis at least one of ammonia, organic amines, pyridine or substitutedpyridine, fluoroamines, or hydroxides.
 59. The method of claim 47,wherein the base catalyst is ammonia.
 60. The method of claim 47,wherein the reaction temperature is at least 100° C.
 61. A method forproducing fine structures of an insulating material, the methodcomprising: forming a solution of a hydrolysable alkoxide and acatalyst, the catalyst comprising an acid or a base, in supercriticalcarbon dioxide; contacting a substrate with the supercritical carbondioxide solution, wherein the substrate comprises structures having highaspect ratios of at least 5; and, reacting the hydrolysable alkoxidewith water to deposit an oxide, wherein the oxide fills the high aspectratio structures.
 62. The method of claim 61, wherein the alkoxidecomprises at least one of the groups of elements consisting of silicon,titanium phosphorus, hafnium, zirconium, aluminum and boron.
 63. Themethod of claim 61 wherein the alkoxide is tetraethyl orthosilicate. 64.The method of claim 61, wherein the alkoxide is hafnium tert-butoxide.65. The method of claim 61, wherein the alkoxide is aluminum ethoxide.66. The method of claim 61, wherein the alkoxide is aluminumisopropoxide.
 67. The method of claim 61, wherein the acid catalyst issoluble in supercritical carbon dioxide or can be rendered soluble whencomplexed with a Lewis base.
 68. The method of claim 67, wherein theacid catalyst is complexed with a Lewis base and the Lewis base istributyl phosphate.
 69. The method of claim 61, wherein the acidcatalyst is acetic acid, formic acid, citric acid, hydrofluoric acid,hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid. 70.The method of claim 61, wherein the acid catalyst is acetic acid. 71.The method of claim 61, wherein the base catalyst is soluble insupercritical carbon dioxide or can be rendered soluble by complexingwith a Lewis acid.
 72. The method of claim 61, wherein the base catalystis at least one of ammonia, organic amines, pyridine or substitutedpyridine, fluoroamines, or hydroxides.
 73. The method of claim 61,wherein the base catalyst is ammonia.
 74. The method of claim 61,wherein the reaction temperature is at least 100° C.
 75. A method ofincreasing the solubility of acids in supercritical carbon dioxide, themethod comprising: combining supercritical carbon dioxide, a Lewis basethat is soluble in supercritical carbon dioxide, and an acid that issubstantially insoluble in supercritical carbon dioxide such that theLewis base and the acid form a complex that is soluble in supercriticalcarbon dioxide.
 76. The method of claim 75, wherein the acid is citricacid, nitric acid, sulfuric acid, or phosphoric acid.
 77. A method ofincreasing the solubility of bases in supercritical carbon dioxide, themethod comprising: combining supercritical carbon dioxide, a Lewis acidthat is soluble in supercritical carbon dioxide, and a base that issubstantially insoluble in supercritical carbon dioxide such that theLewis acid and the base form a complex that is soluble in supercriticalcarbon dioxide.
 78. The method of claim 77, wherein the base is organicamines or substituted pyridines, fluoroamines, potassium hydroxide orsodium hydroxide.
 79. A method for increasing the solubility of water insupercritical carbon dioxide, the method comprising: combiningsupercritical carbon dioxide with an acid or base, wherein the acid orbase is soluble, or solubilizable, in supercritical carbon dioxide andthe acid or base interacts with water to solubilize the water in thesupercritical carbon dioxide.
 80. The method of claim 79, wherein theacid is complexed with a Lewis base and the Lewis base is tributylphosphate.
 81. The method of claim 79, wherein the acid is acetic acid,formic acid, citric acid, hydrofluoric acid, hydrochloric acid, nitricacid, sulfuric acid, or phosphoric acid.
 82. The method of claim 79,wherein the acid is acetic acid.
 83. The method of claim 79, wherein thebase is at least one of ammonia, organic amines, pyridine or substitutedpyridines, fluoroamines, or hydroxides.
 84. The method of claim 79,wherein the base is ammonia.
 85. A method of forming a material having alow dielectric content, the method comprising the steps of: forming asolution of a hydrolysable alkoxide and a catalyst, the catalystcomprising an acid or a base, in supercritical carbon dioxide, andreacting the hydrolysable alkoxide with water to deposit material havinga dielectric constant less than about
 3. 86. The method of claim 85,wherein the deposited material is an oxide that comprises at least oneof fluorine, carbon or porosity.
 87. The method of claim 85, wherein thedeposited material is at least one hybrid glass.
 88. The method of claim87, wherein the hybrid glass is at least one of Ormosil, Ormocer orsilsesquioxane materials.